Title:
A HELICAL BIT TOOL
Document Type and Number:
WIPO Patent Application WO/2009/114958
Kind Code:
A1
Abstract:
A helical bit tool includes a bit head (1) with multiple helical pieces (2). Each helical piece has a side cutting edge (3) which faces on the direction of cutting operation. The surface of the side cutting edge which faces on the direction of cutting operation forms a cutting face (4). The back surface of the cutting face forms a rear cutting face (5). The step area (7) is formed on the top surface (6) of the bit head, in which forming a step or multiple steps with progressively lower heights from the center of the top surface to the outer flank. The periphery of every step is inclined with respect to the periphery of the bit head. A chamfering surface (9) is formed on where the rear cutting face interfaces with the step area and the top surface of the bit head. An upright cutting face (15) is formed on the surface of the chamfering surface near the center of the top surface. The intersection of the chamfering surface, the step area and the top surface of the bit head forms a rear cutting edge (10). The intersection of the upright cutting face and the step area forms a chisel edge (11).
Inventors:
LI, Shiqing (Zhangzhuang Cinema Sushe, XinwenXintai, Shandong, 27219, CN)
Application Number:
CN2008/000546
Publication Date:
September 24, 2009
Filing Date:
March 19, 2008
Export Citation:
Assignee:
LI, Shiqing (Zhangzhuang Cinema Sushe, XinwenXintai, Shandong, 27219, CN)
International Classes:
B23B51/02
Attorney, Agent or Firm:
CCPIT PATENT AND TRADEMARK LAW OFFICE (8th Floor, Vantone New World Plaza2 Fuchengmenwai Street, Beijing 7, 100037, CN)
Download PDF: